EP2928916A1

EP2928916A1 - Novel interleukin-33 inhibitors

Info

Publication number: EP2928916A1
Application number: EP13802636.4A
Authority: EP
Inventors: Rudi Beyaert; Harald Braun; Bart Lambrecht; Hamida HAMMAD
Original assignee: Universiteit Gent; Vlaams Instituut voor Biotechnologie VIB
Current assignee: Universiteit Gent; Vlaams Instituut voor Biotechnologie VIB
Priority date: 2012-12-10
Filing date: 2013-12-10
Publication date: 2015-10-14
Anticipated expiration: 2033-12-10
Also published as: AU2013357427B2; CA2894219A1; EP2928916B1; AU2013357427A1; US20150315262A1; WO2014090800A1; US10703799B2; CA2894219C

Abstract

The present invention relates to novel inhibitors of IL-33. More specifically, it relates to a fusion protein of the soluble IL-33 receptor with the soluble IL-1RAcP as inhibitor of IL-33 activity. The invention relates further to the use of said inhibitor in treatment of IL-33 related diseases such as, but not limited to asthma, atopic dermatitis and psoriasis.

Description

NOVEL INTERLEUKIN-33 INHIBITORS

The present invention relates to novel inhibitors of lnterleukin-33 (IL-33). More specifically, it relates to a fusion protein comprising the soluble IL-33 receptor and the soluble lnterleukin-1 receptor accessory protein (IL-1 RAcP) as inhibitor of IL-33 activity. The invention relates further to the use of said inhibitor in treatment of IL-33 related diseases such as, but not limited to asthma, atopic dermatitis and psoriasis.

lnterleukin-33 (IL-33), also known as IL-1 F1 1 or DVS27, is a member of the IL-1 superfamily of cytokines that is expressed mainly in stromal cells, such as epithelial and endothelial cells. The IL-1 family members and the IL-1 receptor family play an important role in inflammatory and immunological responses. IL-1 superfamily related diseases include asthma, chronic obstructive pulmonary disorder (COPD), rheumatoid arthritis and psoriasis. IL-1 receptors have been used in the treatment of diseases: US 2003/0049255 discloses a method of treating a patient affected with a medical disorder selected from the group consisting of rheumatoid arthritis, Alzheimer's stroke, head trauma, myocardial infarction, heart failure, periodontal disease, inflammatory bowel disease, asthma and pancreatitis by administering a therapeutically effective amount of an IL-1 receptor and lnterleukin-1 receptor accessory protein (IL-1 RAcP), wherein IL-1 RAcP may be soluble IL1 -RAcP.

IL-33 plays a role in inflammation and several diseases, including asthma, rheumatologic diseases, inflammatory skin disorders, inflammatory bowel disease, central nervous inflammation, cancer, cardiovascular diseases (for a review, see Miller, 201 1 )

IL-33 seems to be a cytokine with a dual function, acting both as traditional cytokine and as intracellular nuclear factor with transcriptional regulatory properties (Haraldsen et al., 2009). IL- 33 acts as a cytokine by binding to the ST2L/IL-1 RAcP receptor complex (Chackerian et al. 2007). Signaling is then induced through the cytoplasmic Toll-interleukin receptor domain of IL- 1 RAcP.

IL-33 differs from other IL-1 family members by primarily inducing T helper 2 (Th2) immune responses in a number of immune cell types (Lamkanfi and Dixit, 2009).

In view of its important role in diseases, several strategies have been proposed to control pathogenic IL-33 expression. WO2005079844 discloses IL-33 antagonists, consisting of IL-33 or IL-33 receptor antibodies. Leung et al. (2004) describe a therapy of murine collagen-induced arthritis with soluble ST2, but they didn't study the effect of the soluble receptor on IL-33. Hayakawa et al., (2007) shows that soluble ST2 blocks IL-33 signaling in allergic airway inflammation. However, although some improvement is obtained with these approaches, the blocking of the IL-33 response is rather weak and there is a need for better and stronger antagonists. Surprisingly we found that a fusion protein comprising the soluble IL-33 receptor and the soluble IL-1 RAcP efficiently inhibits the IL-33 response. The inhibition is not only stronger than the inhibition caused by soluble IL-33 receptor or by soluble IL-1 RAcP alone, it is surprisingly also more efficient than a mixture of both soluble receptors.

Therefore, a first aspect of the invention is a fusion protein (referred further also as IL-33trap) comprising the soluble IL-33 receptor and the soluble IL-1 RAcP. The soluble IL-33 receptor and the soluble IL-1 RAcP are known to the person skilled in the art; preferably said soluble IL- 33 receptor is the human soluble IL-33 receptor (SEQ ID N° 4) and the soluble IL-1 RAcP is the human soluble IL-1 RAcP (SEQ ID N° 5). Alternatively, a homologue of those polypeptides may be used. "Homologues" of a protein encompass peptides, oligopeptides, polypeptides, proteins and enzymes having amino acid substitutions, deletions and/or insertions relative to the unmodified protein in question and having similar biological and functional activity as the unmodified protein from which they are derived. The terms protein and polypeptide as used in this application are interchangeable. Polypeptide refers to a polymer of amino acids and does not refer to a specific length of the molecule. This term also includes post-translational modifications of the polypeptide, such as glycosylation, phosphorylation and acetylation. The fusion may be at the aminoterminal or at the carboxyterminal end of the soluble IL-33 receptor. Preferably, both soluble polypeptides are linked with a linker. Even more preferably, said linker is at least 10 amino acids in length. More preferably, said linker consists of GGS repeats, most preferably at least 8 GGS repeats up to 30 GGS repeats. Preferably, said linker consists of at least 10 GGS repeats, even more preferably at least 20 GGS repeats. Most preferably, the fusion protein comprises a sequence selected from the group consisting of SEQ ID N°1 , SEQ ID N°2 and SEQ ID N°3. Alternatively, the fusion protein comprises the human homologues, as represented in SEQ ID N° 6, and SEQ ID N°7

Another aspect of the invention is the use of a fusion protein according to the invention as a medicament. Still another aspect of the invention is a fusion protein according to the invention for use in an IL-33 related disease. IL-33 related diseases are known to the person skilled in the art, and include, but are not limited to asthma, rheumatoid arthritis, osteoarthritis, atopic dermatitis, psoriasis, psoriatic arthritis, systemic lupus erythematosus, inflammatory skin disorders, inflammatory bowel disease and cancer. One preferred embodiment is the fusion protein for use in treatment of asthma. Another preferred embodiment is the fusion protein for use in treatment of atopic dermatitis. Another preferred embodiment is the fusion protein for use in treatment of psoriasis. Another preferred embodiment is the fusion protein for use in treatment of rheumatoid arthritis. Still another preferred embodiment is the fusion protein for use in inflammatory bowel disease. Still another aspect of the invention is the use of a fusion protein according to the invention for the preparation of a medicament, preferably for the preparation of a medicament to treat an IL- 33 related disease, as described above.

Another aspect of the invention is a pharmaceutical composition, comprising a fusion protein according to the invention, optionally with a suitable excipient. Suitable excipients are known to the person skilled in the art, and are inherently non-toxic and nontherapeutic. Excipients may be, as a non-limiting example, Ringer's solution, dextrose solution or Hank's solution. Non aqueous solutions such as fixed oils and ethyl oleate may also be used. A preferred excipient is 5% dextrose in saline. The excipient may contain minor amounts of additives such as substances that enhance isotonicity and chemical stability, including buffers and preservatives. Another aspect of the invention is the use of a fusion protein according to the invention to inhibit IL-33 signaling.

Still another aspect of the invention is a method to treat an IL-33 related disease, as described above, said method comprising (i) providing a pharmaceutical composition according to the invention (ii) applying a suitable amount of said pharmaceutical composition to a patient in need of the treatment.

BRIEF DESCRIPTION OF THE FIGURES

Fig.1 Engineered IL-33 trap, a, Schematic representation of the engineered IL-33 trap. The soluble IL-1 RAcP receptor (blue) is fused to the soluble ST2 receptor. Both receptor components are separated by a flexible linker consisting of Gly-Gly-Ser repeats. The signal peptide (light blue) at the N-terminus ensures secretion of the expressed protein into the medium fraction. A carboxy terminal myc/His6 tag (black) is used for detection and purification, b, western blot analysis of secreted proteins. Conditioned medium from HEK293T cells transiently transfected with empty vector (lane 1 ), pEF-SmlL1 RAcP (lane 2), pEF-mST2s (lane 3) or pEF-mlL33trap (lane 4) were analyzed by western blotting with an anti-His6 antibody. Protein size is indicated in kDa at the left. Due to glycosylation of the expressed proteins, the apparent size is bigger than their theoretical weight.

Fig.2 Purified mST2s and mlL33trap proteins, a, SDS-PAGE analysis and Coomassie blue staining of purified mST2s protein (lane 1 ) and mlL33trap protein (lane 2). Protein sizes are indicated in kDa at the left and right, b, western blot analysis of the same purified proteins. 100ng of each protein (lane 1 : mST2s, lane 2: mlL33trap) was separated by SDS-PAGE, blotted on nitro-cellulose membrane and visualized with an anti-His6 antibody. Protein size is indicated in kDa at the left. Fig.3 mlL33trap proteins are highly potent inhibitors of IL-33 activity in vitro, a, Inhibition of IL- 33 induced NF-kB activity by IL-33 blocking proteins. mlL-33 containing medium was preincubated with conditioned medium from various protein producing HEK293T cells (5% v/v) for 30' prior adding to mST2L/mlL-1 RAcP transfected HEK293T cells. Fold activation of NF-kB activity was calculated relative to transfected, not stimulated (ns) cells, b, Inhibition of IL-33 induced NF-kB activity by purified IL-33 blocking proteins. mST2L/mlL-1 RAcP transfected HEK293T cells were stimulated with 0.5nM mlL-33 (second dark grey bar) or with 0.5nM mlL- 33 which was preincubated with various concentrations of mST2s (light gray bars) or mlL33trap protein (medium gray bars). Fold activation of NF-kB activity was calculated relative to transfected, not stimulated (ns) cells.

Fig.4 Potent inhibition of hlL-33 activity by hlL33trap protein in vitro, a, western blot analysis of secreted proteins. Conditioned medium from HEK293T cells transiently transfected with empty vector (lane 1 ), pEF-hST2s (lane 2), pEF-hlL33trap (20xGGS) (lane 3) or pEF-hlL33trap (8xGGS) (lane 4) were analyzed by western blotting with an anti-His6 antibody. Protein size is indicated in kDa at the left. Due to glycosylation of the expressed proteins, the apparent size is bigger than their theoretical weight., b, Inhibition of hlL-33 induced NF-kB activity by hlL-33 blocking proteins. hlL-33 containing medium was preincubated with conditioned medium from various protein producing HEK293T cells (10% v/v) for 30' prior adding to hST2L transfected HEK293T cells. Fold activation of NF-kB activity was calculated relative to transfected, not stimulated (ns) cells.

EXAMPLES

Materials and methods to the examples

Construction of expression vectors.

pEF-mST2L and pEF-SmlL1 RAcP were constructed as follows. Total RNA was isolated from the mouse macrophage cell line Mf4/4 using TRIzol reagent (Sigma-Aldrich). First strand cDNA was synthesized by reverse transcription (iScript, BioRad). mST2L was PCR amplified with TAQ DNA polymerase (Table 1 : primers 1 and 3) and ligated in pGEM-Teasy, resulting in pGEM-mST2L. The mST2L cDNA was isolated by Xbal digestion from pGEM-mST2L and cloned in the Xbal site of pEF6-myc/HisA (Invitrogen) to obtain the expression vector pEF- mST2L. The coding sequence of soluble ml L1 -RAcP was PCR amplified with TAQ DNA polymerase (Table 1 : primers 4 and 5). After digestion with EcoRI and Xbal the PCR fragment was ligated in the EcoRI/Xbal opened pEF6-myc/HisA vector to obtain the expression plasmid pEF-SmlL1 RAcP. pEF-mST2s was constructed as follows. mST2s was PCR amplified from Origene clone MC204735 (Talbe 1 : primers 1 and 2) and ligated in the Xbal site of pEF6-myc/HisA, resulting in pEF-mST2s.

pEF-mll_33traps were constructed as follows. Soluble mouse ST2 without the signal sequence (amino acids 27-337) was PCR amplified from pEF-mST2s (Table 1 : primers 6 and 7) and digested with Pstl and EcoRV. A linker sequence of repeating Gly-Gly-Ser triplets was PCR amplified from pCLG-Duba (BCCM/LMBP number 6610), which contains 20 Gly-Gly-Ser repeats, with primers 8 and 9 (Table 1 ) and digested with Xbal and Pstl. Both DNA fragments were cloned by a 3-way ligation reaction in the Xbal/Pmel digested pEF-SmlL1 RAcP vector. Three constructs with different linker length (20, 12 or 8 Gly-Gly-Ser repeats) were obtained. All constructs were confirmed to be correct by DNA sequencing analysis.

The expression vector for murine IL1 -RAcP (pCR4-Flag-mlL1 RAcP) was kindly provided by Dr. Sophie Janssens from our department. pEF-hST2s was constructed as follows. hST2s was PCR amplified from pEF-BOS-hST2s (Table 1 : primers 10 and 1 1 ) and ligated in the BamHI / Notl opened pEF6-myc/HisA vector, resulting in pEF-hST2s. DNA sequencing of this constructs revealed a PCR-induced point mutation, leading to the conversion of a methionine to a lysine at position 13 in the signal peptide of hST2s (M13K).

pEF-ShlL1 RAcP was constructed as follows. The coding sequence of soluble hlL1 -RAcP was PCR amplified with TAQ DNA polymerase (Table 1 : primers 12 and 13) from a human spleen cDNA library. After digestion with EcoRI and Xbal the PCR fragment was ligated in the EcoRI/Xbal opened pEF6-myc/HisA vector to obtain the expression plasmid pEF-ShlL1 RAcP. pEF-hlL33traps were constructed as follows. Soluble human ST2 without the signal sequence (amino acids 19-328) was PCR amplified from pEF-hST2s (Table 1 : primers 14 and 7) and digested with Nsil (partially) and EcoRV. A linker sequence of repeating Gly-Gly-Ser triplets was PCR amplified from pCLG-Duba (BCCM/LMBP number 6610), which contains 20 Gly-Gly- Ser repeats, with primers 8 and 9 (Table 1 ) and digested with Xbal and Pstl. Both DNA fragments were cloned by a 3-way ligation reaction in the Xbal/Pmel digested pEF-ShlL1 RAcP vector. Two constructs with different linker length (20 or 8 Gly-Gly-Ser repeats) were obtained. DNA sequencing of the hlL33trap constructs revealed a PCR-induced point mutation, leading to the conversion of a lysine to an arginine at position 41 of the hST2s part of the proteins (K41 R).

pEF-BOS-hST2s and pEF-BOS-hST2L constructs were kindly provided by Prof. Luke O'Neill (Trinity College Dublin, Ireland).

Table 1 Sequences of the primers used for the construction of expression vectors. Expression of soluble receptors and receptor fusion proteins.

HEK293T cells were cultured in DMEM supplemented with 10% FCS and Pen/Strep. 2x10⁵ HEK293T cells were seeded in 6-well plates and transfected the next day by calcium phosphate precipitation with the desired expression vectors. 4h after transfection, the medium was changed and the cells were incubated for 72h at 37^°C. The conditioned medium fractions were analyzed by western blotting with an anti-His antibody (Roche) for the presence of the secreted recombinant proteins and used for IL-33 blocking experiments.

Purification of recombinant mST2s and mlL33trap proteins.

Recombinant mouse ST2s and IL33trap proteins containing a myc/His6 tag at the C terminus were purified by standard chromatographic methods. Briefly, HEK293T cells were transiently transfected with pEF-mST2s or pEF-mll_33trap using the calcium-phosphate method. 16h after transfection the medium was changed and the cells were cultured for 48h in serum free DMEM medium. The secreted recombinant proteins in the medium fractions were concentrated by diafiltration and purified by metal affinity chromatography using nickel-Sepharose. After a final gel-filtration over a Superdex 200 column, the purified proteins were stored in PBS at -80^°C. Protein concentrations were determined by Micro BCA protein assay and the purity of the purified proteins were assayed by SDS-PAGE and western blotting using an anti-His antibody (Roche). In vitro bioassay.

HEK293T cells were cultured in DMEM supplemented with 10% FCS and Pen/Strep. 4x10⁴ HEK293T cells were seeded in 24-well plates and transfected the next day by calcium phosphate precipitation with expression vectors for IL-33Ra (pEF-mST2L) and the coreceptor (pCR4-Flag-mlL1 RAcP) and a NF-kB-luciferase reporter plasmid, rendering the cells responsive to IL-33. For experiments with human IL-33, HEK293T cells were rendered responsive by transfecting pEF-BOS-hST2L. The co-transfected beta-galactosidase reporter plasmid pAct-bgal served as an internal control to normalize the luciferase readout. 4h after transfection the medium was changed and the cells were left overnight. 24h after transfection the cells were stimulated for 5h with a fixed concentration of mouse IL-33 (R&D Systems) or human IL-33 (produced in Pichia pastoris) or left untreated. For IL-33 blocking experiments, the IL-33 containing medium was pre-incubated with the indicated purified recombinant proteins or conditioned medium fractions for 30 minutes at room temperature on a rotating wheel prior adding to the cells. Finally, luciferase activity in the cell lysates was measured by chemiluminescence.

Example 1 : Construction and purification of the mouse IL-33 trap

The engineered mouse IL-33 trap is encoding a fusion protein consisting of the soluble isoforms (extracellular domains) of the murine IL-1 RAcP and ST2 (IL-33Ra) receptor chains, separated by a flexible Gly-Gly-Ser linker (Fig. 1 a). The expressed protein contains the natural signal peptide of the IL-1 RAcP, leading to the secretion of the recombinant protein into the medium fraction when expressed in mammalian cells. The C-terminal myc/His6 tag allows easy detection and purification of the protein from conditioned medium of transfected cells (Fig. 1 b).

mST2s and mlL33trap proteins were purified from conditioned medium of transiently transfected HEK293T cells by standard chromatographic methods to a purity of ~95%, judged by Coomassie blue staining (Fig. 2a). Example 2: mlL33trap is a potent inhibitor of IL-33 in vitro

The potential of the engineered mlL33trap to block the cytokine activity of IL-33 was evaluated in an in vitro bioassay. mlL33trap proteins were compared to mST2s or the combination of mST2s and SmILI RAcP in their ability to block IL-33 induced NF-kB luciferase reporter activation in mST2L/mlL-1 RAcP transfected HEK293T cells. Stimulation of the transfected cells with mlL-33 strongly activates NF-kB reporter expression. Pre-incubation of IL-33 with mST2s reduces its ability to activate NF-κΒ, which is slightly stronger in the presence of the soluble coreceptor Smll_-1 RAcP. The soluble coreceptor alone, however, has no effect on the activity of IL-33. In contrast, pre-incubation with mlL33trap proteins blocked IL-33 activity significantly stronger then mST2s or the combination mST2s/Smll_1 -RAcP (Fig. 2). Amounts of SmlL1 -RAcP, mST2s and mll_33trap were comparable (Fig. 1 b). Amounts of the three different mll_33trap proteins (20xGGS, 12xGGS and 8xGGS with different linker length of 20, 12 or 8 Gly-Gly-Ser repeats, respectively) were comparable.

For purification and further experiments the fusion protein with the shortest linker (8xGGS) was chosen and designated mll_33trap.

For a more quantitative analysis, the same in vitro bioassay was performed with purified mST2s and IL33trap proteins (Fig. 2) as IL-33 blockers. In this experiment (Fig. 3b), where IL- 33 blocking was performed at low molar ratios, mST2s was a rather weak inhibitor of IL-33 activity. Strikingly, mlL33trap was a high-affinity IL-33 blocker which almost completely inhibited IL-33 induced NF-kB activation even at equimolar ratio.

Example 3: hlL33trap is a potent inhibitor of IL-33 in vitro

The potential of the engineered hlL33trap to block the cytokine activity of IL-33 was evaluated in an in vitro bioassay. hlL33trap proteins were compared to hST2s in their ability to block IL- 33 induced NF-kB luciferase reporter activation in hST2L/hlL-1 RAcP transfected HEK293T cells. Stimulation of the transfected cells with hlL-33 strongly activates NF-kB reporter expression. Pre-incubation of IL-33 with hST2s reduces its ability to activate NF-κΒ. The soluble coreceptor alone, however, has no effect on the activity of IL-33. Pre-incubation with hlL33trap proteins blocked IL-33 activity significantly stronger then hST2s (Fig. 4b). In contrast to mlL-33 trap proteins, hlL-33 blocking activity of the hlL33trap proteins is critically dependent on the length of the Gly-Gly-Ser linker: 8xGGS containing hlL-33 trap is not more active than hST2s, whereas 20xGGS containing hlL-33trap is much more potent than hST2s. Amounts of hST2s (Fig. 4a, lane 2) and the two different hlL33trap proteins (20xGGS and 8xGGS with different linker length of 20 or 8 Gly-Gly-Ser repeats, respectively) were comparable (Fig. 4a, lane 3 and 4). Example 4: mlL33trap is a potent inhibitor of allergic asthma

To address the in vivo effect of mlL33trap in allergic asthma (an IL-33 mediated disease), we used a mouse model in which all features of asthma are induced by the allergen house dust mite (HDM). Mice were sensitized intratracheally on day 0 with 1 μg HDM extracts. To ensure the proper blockade of IL-33 locally in the lungs, some mice were administered intratracheally either with 40 μg of soluble mST2s or with 40 μg of mlL33trap (8xGSS linker). On days 7 to 1 1 , mice were re-exposed intranasally to HDM to induce asthma features. On day 14, the bronchoalveolar lavage (BAL) fluids were collected and analyzed for the presence of inflammatory cells (neutrophils, lymphocytes and eosinophils). Mice that were sensitized and challenged with HDM showed a strong recruitment of eosinophils and lymphocytes in the BAL fluids, indicative of allergic asthma development. Mice that were also administered with soluble mST2s showed a 45% reduction in the number of eosinophils and a 24% reduction in the number of lymphocytes, compared to untreated mice. However, mlL33trap administration induced a 55% reduction in the number of eosinophils and a 46% reduction in the number of lymphocytes, compared to untreated mice.

In conclusion, both soluble mST2s and mlL33trap had the potential to reduce features of allergic asthma but mlL-33trap is significantly more potent than mST2s (most pronounced for the inhibitory effect on lymphocyte recruitment to the airways of asthmatic mice).

REFERENCES

Chackerian, A.A., Oldham, E.R., Murphy, E.E., Schmitz, J., Pflanz, S. and Kastelein, R.A. (2007). IL-1 receptor accessory protein and ST2 comprise the IL-33 receptor complex. J. Immunol. 179, 2551 - 2555.

Haraldsen, G., Balogh, J., Pollheimer, J., Sponheim, J. and Kuchler, A.M. (2009). lnterleukin-33 - cytokine of dual function or novel alarmin? Trends Immunol. 30, 227- 233.

- Lamkanfi, M. and Dixit, V.M. (2009). IL-33 raises alarm. Immunity, 31 , 5 - 7.

- Miller, A.M., Role of IL-33 in inflammation anddisease.(201 1 ). J. Inflammation 8, 22-33

Claims

1 . A fusion protein comprising the soluble IL-33 receptor and the soluble IL-1 RAcP.

2. The fusion protein according to claim 1 , wherein said soluble IL-33 receptor and said soluble IL-1 RAcP are connected by a linker

3. The fusion protein according to claim 2, wherein said linker is at least 10 amino acids in length.

4. The fusion protein according to claim 2 or 3, wherein said linker is a GGS linker.

5. The fusion protein according to claim 4, wherein said GGS linker consists of 8-20 GGS units.

6. The fusion protein according to claim 5, wherein said fusion protein comprises a sequence selected from the group consisting of SEQ ID N°1 , SEQ ID N°2 , SEQ ID N° 3, SEQ ID N°6 and SEQ ID N°7

7. The fusion protein according to any of the claims 1 -6 for use as a medicament

8. The fusion protein according to any of the claims 1 -6 for use in treatment of an IL-33 related disease.

9. The fusion protein according to claim 8, wherein said IL-33 related disease is selected from the group consisting of asthma, rheumatoid arthritis, osteoarthritis, atopic dermatitis, psoriasis, psoriatic arthritis, systemic lupus erythematosus, inflammatory skin disorders, inflammatory bowel disease and cancer.

10. A pharmaceutical composition, comprising a fusion protein according to any of the claims 1 -6.

1 1 . The use of a fusion protein according to any of the claims 1 -6 to inhibit IL-33 signaling.